Currently, spectrophotometer can be used to carry out color measurement on large monochrome objects with high accuracy. However, as spectrophotometer has a very low spatial resolution, it cannot be used to measure various types of textile and apparel samples, for example, yarn dyed fabric, lace, textile accessories and printed fabric.
Conventional imaging devices, including digital cameras and color scanners, record color information by passing surface reflected light through a plurality of color filters having different spectral transmittance, and forming images from the reflected light by an electronic sensor. Conventional devices are associated with various advantages for measuring many colors at the same time. They are most commonly used in measuring small, multicolor objects and capturing color information on surface of an object having a complicated texture. However, in one aspect, the traditional primary color and colorimetric imaging systems, due to violation of the Luther Rule, are difficult to produce color images of high accuracy. The Luther Rule refers to spectral sensitivity of most cameras that is not similar to human eyes or linear combination of human eyes. Furthermore, the conventional colorimetric imaging systems can only output tristimulus values, which lead to metamerism errors caused by different observers and different lighting systems. Therefore, these conventional colorimetric measurement systems, such as DigiEye produced by Verivide Corp., do not satisfy the high color quality requirements in textile and apparel industry.